The use of steel-reinforced concrete in building is widespread all around the world. Many developing countries use about 90% and 80% of the cement and steel consumed by the global construction sector respectively. Out of the 54 African nations, only two produce steel; leaving the other 52 countries to compete in the global market for this seemingly irreplaceable material.
However, steel is not irreplaceable as there is an alternative material that grows in the tropical zone of the Earth: bamboo. Bamboo belongs to the botanical family of grasses and is extremely resistant to tensile stress and is therefore one of nature’s most versatile products. This is as a result of its evolution and adaptation to natural forces i.e. wind. The bamboo culm(or haulm), which are botanical terms for the stem of a grass is thin and hollow; this allows it to withstand any natural force it is exposed to. In its ability to withstand tensile forces, bamboo is superior to timber and even to reinforcement steel.
Bamboo is also highly renewable and eco-friendly. It grows much faster than wood, it is easily obtainable and is usually available in great quantities. It is also known for its unrivalled capacity to capture carbon and could therefore play an important role in reducing carbon emissions worldwide. It could strengthen local value chains, bring jobs and trade to the steel-reliant countries, and lower their dependency on international markets.
Despite its strengths, bamboo has a number of weaknesses as a construction material. Water absorption, swelling and shrinking behavior, limited durability, and vulnerability to fungal attacks have limited most applications of bamboo so far. Today, bamboo is generally limited to traditional applications of the culm as a structural component in vernacular architecture; early attempts to use it as an untreated, non-composite reinforcement material in concrete were not successful.
At ETH Singapore’s Future Cities Laboratory (FCL), a team of young researchers is working to tap bamboo’s potential by exploring new types of composite bamboo material. The material’s tensile strength aroused their interest as architects and engineers and inspired them to investigate the possibility of extracting the fiber from the natural bamboo, transforming it into a manageable industrial product, and introducing it as a viable building material, an alternative to steel and timber.
Bamboo composite material can be produced in any of the familiar shapes and forms in which steel and timber are produced. Like them, the material can be used to build wall structures for houses or any other buildings. More interestingly, it can be used for specific applications the take optimum advantage of the material’s tensile strength, such as reinforcement systems in concrete or beams for ceilings and roof structures.
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